Nanotechnology applications in everyday products are expanding and diversifying. While industry processes are designed to minimize or eliminate the release of engineered nanomaterials (ENMs), the widespread use of nano-enabled products means that some nanoforms will enter the environment either directly or from the managed waste stream. In this context, the need arises for proportionate and evidence-based assessment of any associated environmental exposure and possible risks.
Nanomaterial environmental risk assessment exercises to date have focussed on the pristine particles as synthesized, and on the nanoforms as engaged in production processes. This approach overlooked the fact that due to ENMs’ unique properties (nanoscale size resulting in high surface area and reactivity) in most cases when released to the environment they undergo reactions and transformations. Once released from products the nanoforms meet physically and chemically reactive species (suspended organic matter, molecules and ions) in both abiotic and biotic environments (e.g. in waste reactors, air, soil, water, sediment and biotic interfaces, e.g. rhizosphere, gut, gills etc.).
In order to make tangible progress on nano-exposure assessment in the environment and its inclusion in nano-regulation, we must drive towards a pragmatic and realistic approach that also reduces complexity where appropriate. The new REACH annexes recognize the need to move focus away from the physical/chemical properties of pristine ENMs and to seek understanding of the functional and behaviour patterns of ENMs in exposure-relevant environments. NanoFASE meets the challenge by addressing fate and transport in real environments, allowing (as noted by ECHA NMEG-10) the "potentially infinite physicochemical variety of nanomaterials" and their transformation products to be incorporated into a modelling framework for nanomaterial fate and exposure assessment.
|Throughout the project lifetime, NanoFASE scientists have worked to ensure that project advances are fully useful to regulatory processes and the involved stakeholders. Our Advisory Board members have been particularly open and helpful in these interactions. In this way NanoFASE attended e.g. the ECHA Nanomaterials Expert Group (NMEG) 10th meeting in November 2017 to share progress on exposure modelling in view of REACH support. See two PPT presentations at the bottom of this page. NMEG encouraged us to shape the NanoFASE models/approaches for eventual inclusion in the ECHA Guidance as potential or recommended tools to be used in regulatory exposure assessment. NanoFASE similarly joined the November 2018 NMEG "Workshop on supporting the implementation of the REACH information requirements for nanomaterials" (REACH Annexes), giving input to the environmental breakout discussing how guidance for applicants on meeting the future reporting obligations can balance realism, relevance, legislative requirements and feasibility.
NanoFASE scientists have similarly attended OECD Working Party on Manufactured Nanomaterials (WPMN) meetings to share practical insight. on how procedures and protocols are adapted to nano environmental research. Support for guidance on determining the attachment efficiency parameter in soil and water was provided. NanoFASE methodological development of soil column tests will inform an OECD Guidance Document. The NanoFASE Concluding Conference (Sept. 2019) includes a stakeholder breakout session to discuss in detail the methods to be put forward for Technical Guidance or Guidance Documents.
The NanoFASE Clickable Framework provides a host of resources to understand exposure assessment of ENMs in the environment:
- Key processes of transformation that nanomaterials may undergo before, during and after being emitted into the environment;
- Fate descriptors that can be used to quantify rates of nanomaterial transformation in the different compartments or ‘reactors’ of the environment (air, soil, water and biota) as well as waste management installations;
- The NanoFASE Model Catalogue including the NanoFASE water–soil–organism (WSO) model.
Visit the Site Map to get a full overview of the 160 pages available here. They have for the most part been written with a broad range of stakeholders in mind.
While the Clickable Framework is not a live decision-support tool (exposure assessment cannot be run online here) we have included a detailed example of workflow – explaining how our algorithms and models fit into a tiered assessment, moving from "back of envelope" through to precise numbers on the spatiotemporal distribution of nanomaterials. Existing widely-used models – SimpleBox4nano as a leading instrument for second-tier assessment, and the LOTOS–EUROS atmospheric transport and deposition model) – have been refined and enlarged through NanoFASE work. The NanoFASE WSO model itself has been designed to generally require the least possible calibration, and thus be applicable to the broadest range of geographical regions.
See our presentations to ECHA NMEG
Learn about the four-year NanoFASE project, and its major outcomes.
Frank von der Kammer
University of Vienna, Austria